The music manager and talent show judge said he learned a lot from working with 1980 winner Johnny Logan, who he met on a bus on the way to a performance of Joseph and the Amazing Technicolour Dreamcoat.
"Eurovision has been good to me," he told Thornton. "And I've always enjoyed it. It's fun. It's kitsch, it's camp, but it's fun."
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The Westlife manager said he didn't actually think the demo of the winning song 'What's Another Year?' was great but it nevertheless went on to win the Song for Ireland competition and then to win Eurovision.
Walsh also had success with Logan again in 1987, with Linda Martin's 'Why Me?' in 1992 and entered the contest twice with Jedward in 2011 and 2012.
But it was his first win, early in his career, that helped Walsh progress his career. Saying he had never really left Ireland before then, he described travelling with Logan all over Europe and saying he 'learned an awful lot' from working with the singer.
He said: "[Logan] was great fun to work with. I got to go all around Europe with him, because he did all the big TV shows in Germany and France, all over Scandinavia.
"And I'm just going: 'There's a whole life out there.' So that that opened up a lot of doors and gave me loads of ideas."
Of their first meeting, Walsh said: "[We were] on the bus, going to the gig, and we started chatting. And he found out I loved music, and he loved music.
"He said: 'I'd love you to manage me.' And I said: 'I will,' not knowing he had another manager at the time and a contract.
"So I was managing him, getting him small gigs, I was giving him support, and I was giving him belief in himself."
Thornton also said in the episode that Walsh's career began in a phone box, as he spoke about making calls from the payphone in his local town to try and get gigs for the acts he was working with.
Saying he then moved to Dublin because he was 'no good at school' the former X Factor and Popstars: The Rivals judge said he learned his craft working in a showband office, a type of dance band popular through the 80s.
Walsh told her: "If I got the support for the local band, I got into the gig free. We had a night out and we got paid. Sometimes we got laid and paid, nothing wrong with that."
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